Filtered Cigarette With Modifiable Sensory Characteristics

ABSTRACT

A filter element for a smoking article is provided, the filter element including a first segment of fibrous tow filter material; a second segment of fibrous tow filter material in spaced relation to the first segment; and a cavity positioned between the two segments of fibrous tow filter material, the cavity containing a plurality of breakable capsules having an outer shell and an internal payload comprising a flavorant, wherein one segment of fibrous tow filter material includes an adsorbent material dispersed therein and the other segment is substantially free of adsorbent material. A cigarette that includes such a filter element is also provided.

FIELD OF THE INVENTION

The present invention relates to products made or derived from tobacco, or that otherwise incorporate tobacco, and are intended for human consumption. In particular, the invention relates to filter elements for smoking articles such as cigarettes.

BACKGROUND OF THE INVENTION

Popular smoking articles, such as cigarettes, have a substantially cylindrical rod-shaped structure and include a charge, roll or column of smokable material, such as shredded tobacco (e.g., in cut filler form), surrounded by a paper wrapper, thereby forming a so-called “smokable rod” or “tobacco rod.” Normally, a cigarette has a cylindrical filter element aligned in an end-to-end relationship with the tobacco rod. Typically, a filter element comprises plasticized cellulose acetate tow circumscribed by a paper material known as “plug wrap,” and the filter element is attached to one end of the tobacco rod using a circumscribing wrapping material known as “tipping paper.” It also has become desirable to perforate the tipping material and plug wrap, in order to provide dilution of drawn mainstream smoke with ambient air. Descriptions of cigarettes and the various components thereof are set forth in Tobacco Production, Chemistry and Technology, Davis et al. (Eds.) (1999). A cigarette is employed by a smoker by lighting one end thereof and burning the tobacco rod. The smoker then receives mainstream smoke into his/her mouth by drawing on the opposite end (e.g., the filter end) of the cigarette.

Certain filter elements for cigarettes contain materials that alter the chemical composition or sensory characteristics of mainstream smoke. For example, it is known to incorporate certain adsorbent materials into a filter element, such as activated carbon or charcoal materials (collectively, carbonaceous materials) in particulate or granular form. Granules of carbonaceous material can be incorporated into “dalmation” types of filter regions using the general types of techniques used for traditional dalmation filter manufacture. Techniques for production of dalmation filters are known, and representative dalmation filters have been provided commercially by Filtrona Greensboro Inc. Alternatively, granules of carbonaceous material can be incorporated into “cavity” types of filter regions using the general types of techniques used for traditional “cavity” filter manufacture. Various types of filters incorporating charcoal particles or activated carbon types of materials are set forth in U.S. Pat. Nos. 2,881,770 to Touey; 3,101,723 to Seligman et al.; 3,236,244 to Irby et al.; 3,311,519 to Touey et al.; 3,313,306 to Berger; 3,347,247 to Lloyd; 3,349,780 to Sublett et al.; 3,370,595 to Davis et al.; 3,413,982 to Sublett et al.; 3,551,256 to Watson; 3,602,231 to Dock; 3,972,335 to Tigglebeck et al.; 5,360,023 to Blakley et al.; 5,909,736 to Stpyridis; and 6,537,186 to Veluz; US Pat. Publication Nos. 2003/0034085 to Spiers et al.; 2003/0106562 to Chatterjee; 2005/0066982 to Clark et al; 2006/0025292 to Hicks et al.; 2007/0056600 to Coleman, III et al.; 2008/0142028 to Fagg; 2008/0173320 to Dunlap et al.; 2008/0295853 to Jones; 2009/0288672 to Hutchens; PCT WO 2006/064371 to Banerjea et al.; PCT WO 2006/051422 to Jupe et al.; and PCT WO2006/103404 to Cashmore et al., which are incorporated herein by reference.

Cigarette filter elements that incorporate adsorbent materials such as activated carbon are capable of removing certain gas phase components from the mainstream smoke that passes through the filter element during draw by the smoker. The interaction between the adsorbent material and mainstream smoke can result in changes in the sensory properties of the smoke. For example, mainstream tobacco smoke that is filtered using a conventional cigarette filter element incorporating carbon can often be characterized as having slightly metallic, drying and powdery flavor characteristics.

It would be highly desirable to provide a filter element for a smoking article that includes an adsorbent capable of altering the chemical makeup or sensory characteristics of mainstream smoke, and which is designed to provide the smoker with the ability to modify the sensory characteristics of mainstream smoke during use so that any perceived negative sensory traits can be selectively counteracted by the smoker.

SUMMARY OF THE INVENTION

The present invention relates to a filter element for a smoking article such as a cigarette. The smoking article includes a lighting end (i.e., an upstream end) and a mouth end (i.e., a downstream end). A mouth end piece is located at the extreme mouth end of the smoking article, and the mouth end piece allows the smoking article to be placed in the mouth of the smoker to be drawn upon. The mouth end piece has the form of a filter element comprising a cavity containing one or more rupturable, flavorant-containing capsules, and further comprising an adsorbent material positioned between the cavity containing the capsules and the tobacco rod. The filter element of the invention is configured such that the capsules are positioned in a cavity downstream of the adsorbent material so that the smoker can selectively adjust the sensory characteristics of mainstream smoke leaving the adsorbent-containing region of the filter element. The filter element may also include an optional additional particulate material mixed with the capsules, the particulate material being adapted for assisting rupture of the capsules.

In one aspect, the invention provides a filter element of a smoking article, comprising:

(a) a first segment of fibrous tow filter material;

(b) a second segment of fibrous tow filter material in spaced relation to the first segment; and

(c) a cavity positioned between the two segments (a) and (b) of fibrous tow filter material, the cavity containing a plurality of breakable capsules comprising an outer shell and an internal payload comprising a flavorant,

wherein segment (a) of fibrous tow filter material comprises an adsorbent material (e.g., a carbonaceous material) dispersed therein and segment (b) is substantially free of adsorbent material. Exemplary adsorbent materials include activated carbon, molecular sieves, clay, ion exchange resins, activated alumina, silica gel, meerschaum, oxidation catalysts, and combinations thereof.

The flavorant can be, for example, vanilla, coffee, chocolate, cream, mint, spearmint, menthol, peppermint, wintergreen, lavender, cardamon, nutmeg, cinnamon, clove, cascarilla, sandalwood, honey, jasmine, ginger, anise, sage, licorice, lemon, orange, apple, peach, lime, cherry, eucalyptus, strawberry, or mixtures thereof. In certain embodiments, the flavorant is a cooling agent. In one embodiment, the flavorant is menthol.

The payload of the capsules can be anhydrous. In certain embodiments, the payload of the capsules comprises a mixture of the flavorant with a diluting agent, such as a mixture of C6-C12 triglycerides.

Although the shape and size of the capsules can vary, in one embodiment, the capsules are generally spherical in shape with a diameter in the range of about 0.75 mm to about 2.5 mm. The cavity typically contains a sufficient number of capsules such that the void space remaining in the cavity is less than about 50 percent of the volume of the cavity, or less than about 30 percent of the volume of the cavity. Although the thickness of the shell of the capsules can vary, the shell thickness is typically in the range of about 50 to about 200 microns, and the ratio of the diameter of the capsule to the thickness of the shell is about 10 to about 100. In one embodiment, the filter element includes about 20 to about 120 generally spherical capsules having a diameter in the range of about 1 mm to about 1.5 mm.

The crush strength of the capsules can vary, but should provide sufficient physical integrity such that the capsules can withstand conditions associated with cigarette filter storage and manufacture without undue levels of breakage. However, the crush strength of the capsules is preferably low enough to allow the user of the product to rupture the capsules by applying external pressure on the filter element. An exemplary crush strength range is about 0.1 to about 4.0 kilopond (kp), such as about 0.2 to about 1.5 kp.

Exemplary shell materials for the capsule include gelatin, gum arabic, polyvinyl acetate, alginates, carob bean gum, potassium citrate, carrageenan, citric acid, dextrin, polyvinyl alcohol, povidone, dimethylpolysiloxane, dimethyl silicone, bleached shellac, guar gum, gellan gum, agar, ghatti gum, mannan gum, pullulan gum, modified starch, cellulosic materials, sodium citrate, sodium ferrocyanide, locust bean gum, polyphosphates, tannic acid, petroleum wax, terpene resin, tragacanth, polyethylene, xanthan gum, polyethylene glycol, and combinations thereof. In one embodiment, the shell of the capsule comprises a hydrocolloid selected from the group consisting of gellan gum, agar, carrageenan, alginate, arabic gum, pectin, pullulan gum, mannan gum, and combinations thereof, optionally in combination with gelatin. The capsule may also include an outer moisture barrier coating.

The length of each segment of the filter element may vary, but in one embodiment, the length of the first segment of fibrous tow filter material (a) is about 8 mm to about 12 mm, the length of the cavity (c) is about 5 mm to about 8 mm, and the length of second segment of fibrous tow filter material (b) is about 8 to about 12 mm. The combined pressure drop across the first segment (a), the second segment (b), and the cavity (c) is often between about 80 mm water and about 120 mm water, and the pressure drop across the first segment (a) is typically the same or higher than the pressure drop across the second segment (b). For example, the pressure drop across the first segment (a) can be about 40 to about 80 mm water and the pressure drop across the second segment (b) can be about 15 mm water to about 45 mm water.

In yet another embodiment, the invention provides a filter element of a smoking article, comprising:

(a) a first segment of cellulose acetate tow filter material;

(b) a second segment of cellulose acetate tow filter material in spaced relation to the first segment; and

(c) a cavity positioned between the two segments (a) and (b) of fibrous tow filter material, the cavity containing a plurality of breakable capsules comprising an outer shell and an internal payload comprising a flavorant (e.g., menthol) and a diluting agent, wherein the cavity contains about 20 to about 120 generally spherical capsules having a diameter in the range of about 1 mm to about 1.5 mm and a crush strength in the range of about 0.2 to about 1.5 kp;

wherein segment (a) of fibrous tow filter material comprises a carbonaceous material dispersed therein and segment (b) is substantially free of carbonaceous material.

In another aspect, the invention provides a cigarette comprising a tobacco rod having a smokable filler material contained within a circumscribing wrapping material and a filter element according to the invention connected to the tobacco rod at one end of the tobacco rod.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to assist the understanding of embodiments of the invention, reference will now be made to the appended drawings, which are not necessarily drawn to scale. The drawings are exemplary only, and should not be construed as limiting the invention.

FIG. 1 is an exploded perspective view of a smoking article having the form of a cigarette, showing the smokable material, the wrapping material components, and the filter element of the cigarette; and

FIG. 2 is a partial cross-sectional view of a cigarette of the invention wherein the filter element includes an adsorbent material and a plurality of capsules.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present inventions now will be described more fully hereinafter with reference to the accompanying drawings. The invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like numbers refer to like elements throughout. As used in this specification and the claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise.

The invention provides smoking articles, such as cigarettes, having a filter element that combines an adsorbent material with one or more rupturable capsules containing a flavorant. The flavorant-containing capsules, also referred to herein as “flavor capsules,” are typically provided downstream from the adsorbent material such that the flavorant in the capsules can modify the sensory characteristics of mainstream smoke received from the adsorbent-containing region of the cigarette filter prior to the mainstream smoke exiting the extreme mouth end of the cigarette. The capsules are designed to encapsulate the flavorant until ruptured by the smoker. Encapsulation of the flavorant protects the flavorant from degradation during manufacture and storage of the smoking article and enables the smoker to selectively alter the sensory characteristics of the smoking article at any time before, during, or after use.

Referring to FIG. 1, there is shown a smoking article 10 in the form of a cigarette and possessing certain representative components of a smoking article of the present invention. The cigarette 10 includes a generally cylindrical rod 12 of a charge or roll of smokable filler material (e.g., about 0.3 to about 1.0 g of smokable filler material such as tobacco material) contained in a circumscribing wrapping material 16. The rod 12 is conventionally referred to as a “tobacco rod.” The ends of the tobacco rod 12 are open to expose the smokable filler material. The cigarette 10 is shown as having one optional band 22 (e.g., a printed coating including a film-forming agent, such as starch, ethylcellulose, or sodium alginate) applied to the wrapping material 16, and that band circumscribes the cigarette rod in a direction transverse to the longitudinal axis of the cigarette. That is, the band 22 provides a cross-directional region relative to the longitudinal axis of the cigarette. The band 22 can be printed on the inner surface of the wrapping material (i.e., facing the smokable filler material), or less preferably, on the outer surface of the wrapping material. Although the cigarette can possess a wrapping material having one optional band, the cigarette also can possess wrapping material having further optional spaced bands numbering two, three, or more.

At one end of the tobacco rod 12 is the lighting end 18, and at the mouth end 20 is positioned a filter element 26. The filter element 26 positioned adjacent one end of the tobacco rod 12 such that the filter element and tobacco rod are axially aligned in an end-to-end relationship, preferably abutting one another. Filter element 26 may have a generally cylindrical shape, and the diameter thereof may be essentially equal to the diameter of the tobacco rod. The ends of the filter element 26 permit the passage of air and smoke therethrough.

A ventilated or air diluted smoking article can be provided with an optional air dilution means, such as a series of perforations 30, each of which extend through the tipping material 44 (see FIG. 2) and plug wrap 28. The optional perforations 30 can be made by various techniques known to those of ordinary skill in the art, such as laser perforation techniques. Alternatively, so-called off-line air dilution techniques can be used (e.g., through the use of porous paper plug wrap and pre-perforated tipping paper).

An exemplary filter element 26 configuration is shown in FIG. 2, the filter including a first longitudinally-extending filter segment 32 adjacent to the tobacco rod 12 and a second longitudinally-extending filter segment 36 forming the extreme mouth end of filter element. The two segments of filter material 32, 36 define a cavity or compartment 34 centrally located in the filter element. The cavity 34 contains one or more flavor capsules 44 capable of being ruptured during use of the smoking article. Each segment of filter material 32, 36 typically comprises a fibrous tow filter material (e.g., cellulose acetate tow impregnated with a plasticizer such as triacetin). The fibrous tow filter material of the tobacco end segment of filter material 32 includes an adsorbent material 50 dispersed throughout the fibrous material (e.g., a “dalmation” filter segment). The mouth end segment of filter material 36 is typically substantially free of adsorbent material (e.g., containing less than about 0.5 weight percent of such materials based on the total weight of the filter segment) and often completely free of such materials.

The filter element 26 is circumscribed along its outer circumference or longitudinal periphery by a layer of outer plug wrap 28. The filter element 26 is attached to the tobacco rod 12 using tipping material 46 that typically circumscribes both the entire length of the filter element 26 and an adjacent region of the tobacco rod 12. The inner surface of the tipping material 46 is fixedly secured to the outer surface of the plug wrap 28 and the outer surface of the wrapping material 16 of the tobacco rod, using a suitable adhesive; and hence, the filter element and the tobacco rod are connected to one another. Although three regions or segments 32, 34, 36 are shown in the exemplified filter element of FIG. 2, additional filter segments could be added without departing from the invention, such as an additional filter segment at the extreme mouth end or tobacco end of the filter element.

During use, the smoker lights the lighting end 18 of the cigarette 10 using a match or cigarette lighter. As such, the smokable material 12 begins to burn. The mouth end 20 of the cigarette 10 is placed in the lips of the smoker. Thermal decomposition products (e.g., components of tobacco smoke) generated by the burning smokable material 12 are drawn through the cigarette 10, through the filter element 26, and into the mouth of the smoker. Certain gaseous components of mainstream smoke will interact with the adsorbent material 50 such that the chemical composition of mainstream smoke will change as the smoke passes through the adsorbent-containing region of the filter element 26. As the mainstream smoke continues to pass through the filter element 26, the smoke will pass through the flavor capsule region 34 of the filter element. The smoker can selectively adjust the sensory characteristics of the mainstream smoke at any time by applying pressure to the capsule-containing region 34 of the filter element 26 sufficient to cause rupture of at least a portion of the capsules therein. Rupture of the capsules 44 will result in release of the flavorful or aromatic payload within the capsules, which will change the smoker's sensory experience during use of the cigarette. For embodiments containing multiple capsules 44, the smoker can adjust the intensity of the change in sensory characteristics of the smoke by applying different levels of pressure. For example, if the smoker prefers a relatively mild adjustment to the flavor of the smoke, a light pressure that ruptures only a small percentage of the capsules 44 can be applied. If a greater degree of flavor intensity is desired, a greater level of pressure can be applied in order to rupture a larger percentage of the capsules 44.

As used herein, “adsorbent material” refer to any material capable of changing the chemical composition of mainstream smoke through physical or chemical sorption of gaseous components of mainstream smoke or through chemical reaction between the adsorbent material and one or more gaseous components of mainstream smoke. Certain useful adsorbent materials are materials with relatively high surface area capable of adsorbing smoke constituents with or without a high degree of specificity. Exemplary types of adsorbent material may include activated carbon, a molecular sieve (e.g., zeolites and carbon molecular sieves), clay, an ion exchange resin, activated alumina, silica gel, meerschaum, and combinations thereof.

A preferred adsorbent is a carbonaceous material, such as an activated carbon material. Exemplary activated carbon materials have surface areas of more than about 200 m²/g, often more than about 1000 m²/g, and frequently more than about 1500 m²/g, as determined using the Brunaver, Emmet and Teller (BET) method described in J. Amer. Chem. Soc., Vol. 60(2), pp. 309-319 (1938). Suitable examples of such carbonaceous materials are disclosed, for example, in EP 913100 to Jung et al.; WO 2008/043982 to Tennison et al.; WO 2007/104908 to White et al.; WO 2006/103404 to Cashmore et al.; and WO 2005/023026 to Branton et al.; and U.S. Pat. No. 7,370,657 to Zhuang et al., which are incorporated by reference herein.

Activated carbon can be derived from synthetic or natural sources. Materials such as rayon or nylon can be carbonized, followed by treatment with oxygen to provide activated carbonaceous materials. Materials such as wood or coconut shells can be carbonized, followed by treatment with oxygen to provide activated carbonaceous materials. The level of activity of the carbon may vary. Typically, the carbon has an activity of about 60 to about 150 Carbon Tetrachloride Activity (i.e., weight percent pickup of carbon tetrachloride). Preferred carbonaceous materials are provided by carbonizing or pyrolyzing bituminous coal, tobacco material, softwood pulp, hardwood pulp, coconut shells, almond shells, grape seeds, walnut shells, macadamia shells, kapok fibers, cotton fibers, cotton linters, and the like. Examples of suitable carbonaceous materials are activated coconut hull based carbons available from Calgon Corp. as PCB and GRC-11 or from PICA as G277, coal-based carbons available from Calgon Corp. as S-Sorb, Sorbite, BPL, CRC-11F, FCA and SGL, wood-based carbons available from Westvaco as WV-B, SA-20 and BSA-20, carbonaceous materials available from Calgon Corp. as HMC, ASC/GR-1 and SC II, Witco Carbon No. 637, AMBERSORB 572 or AMBERSORB 563 resins available from Rohm and Haas, and various activated carbon materials available from Prominent Systems, Inc. See, also, for example, Activated Carbon Compendium, Marsh (Ed.) (2001), which is incorporated herein by reference.

Various types of charcoals and activated carbon materials suitable for incorporation into cigarette filters, various other filter element component materials, various types of cigarette filter element configurations and formats, and various manners and methods for incorporating carbonaceous materials into cigarette filter elements, are set forth in U.S. Pat. Nos. 3,217,715 to Berger et al.; 3,648,711 to Berger et al.; 3,957,563 to Sexstone; 4,174,720 to Hall; 4,201,234 to Neukomm; 4,223,597 to Lebert; 4,771,795 to White, et al.; 5,027,837 to Clearman, et al.; 5,137,034 to Perfetti et al.; 5,360,023 to Blakley et al.; 5,568,819 to Gentry et al.; 5,622,190 to Arterbery et al.; 6,537,186 to Veluz; 6,584,979 to Xue et al.; 6,761,174 to Jupe et al.; 6,789,547 to Paine III; and 6,789,548 to Bereman; US Pat. Appl. Pub. Nos. 2002/0166563 to Jupe et al.; 2002/0020420 to Xue et al.; 2003/0200973 to Xue et al.; 2003/0154993 to Paine et al.; 2003/0168070 to Xue et al.; 2004/0194792 to Zhuang et al.; 2004/0226569 to Yang et al.; 2004/0237984 to Figlar et al.; 2005/0133051 to Luan et al.; 2005/0049128 to Buhl et al.; 2005/0066984 to Crooks et al.; 2006/0144410 to Luan et al.; 2006/0180164 to Paine, III et al.; and 2007/0056600 to Coleman, III et al.; European Pat. Appl. 579410 to White; and PCT WO 2006/064371 to Banerjea et al.; which are incorporated herein by reference. Representative types of cigarettes possessing filter elements incorporating carbonaceous materials have been available as “Benson & Hedges Multifilter” by Philip Morris Inc., in the State of Florida during 2005 as a Philip Morris Inc. test market brand known as “Marlboro Ultra Smooth,” and as “Mild Seven” by Japan Tobacco Inc.

Exemplary ion exchange resins comprise a polymer backbone, such as styrene-divinylbenzene (DVB) copolymers, acrylates, methacrylates, phenol formaldehyde condensates, and epichlorohydrin amine condensates, and a plurality of electrically charged functional groups attached to the polymer backbone, and can be a weak base anion exchange resin or a strong base anion exchange resin. Commercially available embodiments of such resins include DIAION® ion-exchange resins available from Mitsubishi Chemical Corp. (e.g., WA30 and DCA11), DUOLITE® ion exchange resins available from Rohm and Haas (e.g., DUOLITE® A7), and XORBEX resins available from Dalian Trico Chemical Co. of China.

The adsorbent material can also be in the form of an oxidation catalyst capable of oxidizing one or more gaseous species present in mainstream smoke, such as carbon monoxide, nitrogen oxides, hydrogen cyanide, catechol, hydroquinone, or certain phenols. The oxidation catalyst used in the invention is typically a catalytic metal compound (e.g., cerium oxide) that oxidizes one or more gaseous species of mainstream smoke. Exemplary catalytic metal compounds are described in U.S. Pat. Nos. 4,182,348 to Seehofer et al; 4,317,460 to Dale et al.; 4,956,330 to Elliott et al.; 5,050,621 to Creighton et al.; 5,258,340 to Augustine et al.; 6,503,475 to McCormick; 6,503,475 to McCormick, 7,011,096 to Li et al.; 7,152,609 to Li et al.; 7,165,553 to Luan et al.; 7,228,862 to Hajaligol et al.; 7,509,961 to Saoud et al.; 7,549,427 to Dellinger et al.; 7,560,410 to Pillai et al.; and 7,566,681 to Bock et al.; and US Pat. Publication Nos. 2002/0167118 to Billiet et al.; 2002/0172826 to Yadav et al.; 2002/0194958 to Lee et al.; 2002/014453 to Lilly Jr., et al.; 2003/0000538 to Bereman et al.; 2005/0274390 to Banerjee et al.; 2007/0215168 to Banerjee et al.; 2007/0251658 to Gedevanishvili et al.; and 2010/0065075 to Banerjee et al., and U.S. patent application Ser. Nos. 12/274,780, filed Nov. 20, 2008 to Banerjee et al., and 12/274,818 filed Nov. 20, 2008 to Sears et al., all of which are incorporated by reference herein in their entirety.

Typically, the amount of adsorbent material (e.g., carbonaceous material) within the filter element is at least about 10 mg, often at least about 15 mg, and frequently at least about 20 mg, on a dry weight basis. Typically, the amount of carbonaceous material or other adsorbent material within the filter element does not exceed about 500 mg, generally does not exceed about 400 mg, often does not exceed about 300 mg, and frequently does not exceed about 150 mg, on a dry weight basis.

The form of the adsorbent material can vary, but is typically granular. However, other forms, such as fibers, can also be used. In one embodiment, the adsorbent material is in the form of granules having a particle size of about 10 Mesh to about 400 Mesh, more preferably about 30 Mesh to about 200 Mesh.

Although the adsorbent material is shown in a dalmation-style fibrous filter segment in FIG. 2, the adsorbent material could also be placed in a cavity or compartment upstream of the flavor capsule cavity, or incorporated into paper or other sheet-like material (e.g., as a longitudinally disposed segment of gathered, shredded, or otherwise configured paper-like material).

The flavor capsules used in the invention can be any encapsulated flavorant in a form that provides protection for the flavorant during storage and which allows selective release of the flavorant upon physical destruction or breakage of the capsule by the smoker. Typically, the breakable capsules used in the invention include an outer cover or shell surrounding a central payload region that includes the flavorant. The outer shell is typically susceptible to some type of physical destruction, breakage, or other loss of physical integrity (e.g., through dispersion, softening, crushing, application of pressure, or the like) that can be initiated by the smoker such that the flavorant payload is released in order to change the sensory properties of mainstream smoke passing through the filter element.

The flavor capsules optionally can be mixed within the filter cavity with a particulate material that can act to assist in rupture of the capsules at the desired time due to frictional contact with the capsules or other physical interaction between the particles and the capsules that occurs by virtue of those particles being in close physical proximity to the capsules. The particles can vary in their shapes, and representative shapes can include spherical, prismic, or the like. The particles also can be of irregular shapes, sizes and surface features in order to facilitate capsule rupture. Typically, the particles are of approximately comparable sizes to those of the capsules such that the same general size ranges set forth herein for the capsules can be used for the particulate materials as well. Exemplary particulate materials include cellulose acetate tow beads or pellets, polyvinyl acetate beads, polyethylene beads, polypropylene beads, sepiolite particles, menthol crystals, rock salt crystals, crystalline sugar, cyclodextran particles, corundum particles, quartz crystals, metal beads (e.g., copper or stainless steel), pumice, agglomerated calcium carbonate, microcrystalline cellulose particles, and the like.

As used herein, a “flavorant” or “flavoring agent” is any flavorful or aromatic substance capable of altering the sensory characteristics associated with the smoking article upon release from encapsulation. Exemplary sensory characteristics that can be modified by the flavorant include, taste, mouth feel, moistness, coolness/heat, and/or fragrance/aroma. The flavorant can add desirable taste or aroma attributes to the mainstream smoke, or can serve as a breath freshening agent for the smoker or as a deodorizing agent for the cigarette butt.

The form of the capsule payload can vary. The payload typically has the form of a liquid, a gel, or a solid (e.g., a dry powder). In one embodiment, the payload is a mixture of a flavorant and a diluting agent or carrier. Exemplary diluting agents include alcohols (e.g., ethanol) and lipophilic solvents such as triglycerides (e.g., medium chain triglycerides including food grade mixtures of medium chain triglycerides). An exemplary triglyceride diluting agent is a mixture of C6-C12 triglycerides. See, for example, Radzuan et al., Porim Bulletin, 39, 33-38 (1999). In certain embodiments, the payload can be described as anhydrous, meaning the payload is substantially free of water (e.g., less than about 0.5% by weight water). The payload may also incorporate other additives, such as fillers (e.g., wood resins) or colorants.

The flavorants incorporated within the filter element can be natural or synthetic, and the character of these flavors can be described as, without limitation, fresh, sweet, herbal, confectionary, floral, fruity or spice. Specific types of flavors include, but are not limited to, vanilla, coffee, chocolate, cream, mint, spearmint, menthol, peppermint, wintergreen, lavender, cardamon, nutmeg, cinnamon, clove, cascarilla, sandalwood, honey, jasmine, ginger, anise, sage, licorice, lemon, orange, apple, peach, lime, cherry, and strawberry. See also, Leffingwill et al., Tobacco Flavoring for Smoking Products, R.J. Reynolds Tobacco Company (1972). Flavorings also can include components that are considered moistening, cooling or smoothening agents, such as eucalyptus. These flavors may be provided neat (i.e., alone) or in a composite (e.g., spearmint and menthol, or orange and cinnamon). Composite flavors may be combined in a single capsule as a mixture, or as separate components within separate capsules combined in the same filter element.

The amount of flavoring and diluting agent within the capsule may vary. In some instances, the diluting agent may be eliminated altogether, and the entire payload can be composed of flavoring agent. Alternatively, the payload can be almost entirely comprised of diluting agent, and only contain a very small amount of relatively potent flavoring agent. In one embodiment, the composition of the mixture of flavoring and diluting agent is in the range of about 5 percent to about 75 percent flavoring agent, and more preferably in the range of about 5 to about 25 percent flavoring agent, and most preferably in the range of about 10 to about 15 percent, by weight based on the total weight of the payload, with the balance being diluting agent.

The size and weight of each capsule may vary depending upon the desired properties that the capsules will impart to the cigarette. Certain types of capsules are generally spherical in shape. However, suitable capsules may have other types of shapes, such as generally rectilinear, oblong, elliptical, or oval shapes. Exemplary generally spherical capsules have diameters in the range of about 0.25 mm to about 3 mm in diameter, typically about 0.75 mm to about 2.5 mm. A plurality of very small capsules, commonly referred to as “microcapsules,” can be incorporated within the filter element. Certain microcapsules utilized in the invention can be described as granular in size and are barely visible to the naked eye. Exemplary microcapsules may have diameters of less than about 100 microns, such as capsules having diameters in the range of about 1 to about 40 microns, or about 1 micron to about 20 microns.

The thickness of the shell of each capsule can vary, but is typically in the range of about 10 to about 500 microns, more often about 50 to about 200 microns. The ratio of the diameter of the capsule to the thickness of the shell is typically about 5 to about 150, more often about 10 to about 100.

The number of capsules incorporated into the filter element can vary, depending upon factors such as the size of the capsules, the character or nature of the flavoring agent, the positioning of the capsules within the filter element, and the like. The filter may contain a single capsule, or more preferably, the filter may contain more than one capsule (i.e., a plurality of capsules) or more than two capsules or more than three capsules.

The total number of particles (e.g., capsules and any optional additional particulate materials) incorporated within the relevant region of the filter element can exceed about 5, can exceed about 10, can exceed about 20, can exceed about 40, and can even exceed about 100. In certain embodiments, the number of capsules and other particles can be greater than about 500, and even greater than about 1,000.

The total weight of the particles (i.e., capsules and optional additional particulate materials) contained within the filter may vary, but is typically greater than about 10 mg, often greater than about 20 mg, and can be greater than about 40 mg. The total weight of the capsules is typically less than about 200 mg, often less than about 150 mg, and can be less than about 100 mg.

A representative filter possesses a generally cylindrically shaped cavity region for insertion of capsules, and such a cavity most preferably incorporates a substantial number of capsules. For example, such a cavity can be filled to varying degrees of capacity by using generally spherical capsules. In such a circumstance, sufficient numbers of capsules (and other optional particulate materials) are incorporated into the cavity so that less than about 60 percent, frequently less than about 50 percent, often less than about 35 percent, generally less than about 30 percent of the volume of the cylindrical cavity is comprised of the air space or void space between capsules that are packed or positioned within the cavity.

A representative cavity having a length of about 5 mm and a circumference of about 24 mm can incorporate at least about 20, typically at least about 30, generally at least about 40, and often at least about 50 generally spherical capsules or other particles that have diameters in the range of about 1 mm to about 1.5 mm, preferably about 1.1 mm, about 1.2 mm, or about 1.3 nm. Typically, such a cavity is not filled with more than about 120 capsules (and optional additional particulate materials), often not filled with more than about 100 capsules, and frequently not filled with more than about 80 capsules, depending on the size of the capsules.

In embodiments wherein an optional particulate material is mixed with the capsules to facilitate rupture of the capsules, the additional particulate material typically comprises less than about 75% of the total number of particles in the filter element cavity (i.e., less than about 75% of the combined total number of capsules and additional particles in the cavity), frequently less than about 50% of the total number of particles, and often less than about 25% of the total number of particles.

The capsules that are positioned within the cavity all can have essentially equal dimensions (e.g., capsules of identical circumference and diameter for spherical capsules); while alternatively, the capsules can be of multi-modal dimension (e.g., a mixture of spherical capsules of differing circumference and diameter). An exemplary mixture of spherical capsules having differing sizes includes a mixture of generally spherical capsules having a diameter in the range of about 0.75 to about 1.2 mm and generally spherical capsules having a diameter in the range of about 1.5 to about 2.5 mm.

Larger numbers of capsules in certain embodiments can be advantageous because it can provide the smoker with increased control over flavor release. As opposed to a filter containing a single capsule, the presence of a plurality of capsules allows the smoker to vary the flavor release by continued manipulation of the filter, thereby crushing more capsules and releasing additional flavoring agent.

The crush strength of the capsules used in the invention should be sufficiently high to enable the capsules to withstand conditions experienced during storage, and during the processing associated with incorporating the capsules within a filter element, without a significant degree of premature or undesirable breakage. The crush strength of the capsules should also be sufficiently low so as to allow the smoker to readily break the capsules in a purposeful manner during use of the cigarette. Providing capsules that possess both suitable integrity and ability to rupture can be determined by experimentation, depending upon factors such as capsule size and type, and is a matter of design choice. Exemplary crush strength ranges include about 0.1 to about 4.0 kilopond (kp), typically about 0.2 to about 2.5 kp, often about 0.2 to about 1.5 kp. Crush strength can be measured using a Dr. Schleuniger® Model 5Y Pharmatron Tablet Tester.

The capsules used in the invention can be formed using any encapsulation technology known in the art. For example, capsules can be formed using any of various chemical encapsulation techniques such as solvent evaporation, solvent extraction, organic phase separation, interfacial polymerization, simple and complex coacervation, in-situ polymerization, liposome encapsulation, and nanoencapsulation. Alternatively, physical methods of encapsulation could be used, such as spray coating, pan coating, fluid bed coating, annular jet coating, spinning disk atomization, spray cooling, spray drying, spray chilling, stationary nozzle coextrusion, centrifugal head coextrusion, or submerged nozzle coextrusion.

In addition to the encapsulation methodology employed, the outer wall or shell material and solvents used to form the capsules of the invention can vary. Classes of materials that are typically used as wall or shell materials include proteins, polysaccharides, starches, waxes, fats, natural and synthetic polymers, and resins. Exemplary materials for use in the encapsulation process used to form the capsules include gelatin, acacia (gum arabic), polyvinyl acetate, alginates (e.g., sodium alginate or potassium alginate), carob bean gum, potassium citrate, carrageenan, citric acid, dextrin, polyvinyl alcohol, povidone, dimethylpolysiloxane, dimethyl silicone, bleached shellac, guar gum, gellan gum, agar, ghatti gum, mannan gum, pullulan gum, modified starch, cellulosic materials (e.g., sodium carboxymethylcellulose, ethylcellulose, hydroxypropyl cellulose, hydroxypropylmethylcellulose, methylcellulose, methyl ethyl cellulose), sodium citrate, sodium ferrocyanide, locust bean gum, polyphosphate materials (e.g., sodium trimetaphosphate, sodium tripolyphosphate, potassium polymetaphosphate, potassium tripolyphosphate), tannic acid, petroleum wax (e.g., refined paraffin wax or microcrystalline wax), terpene resin, tragacanth, polyethylene, xanthan gum, polyethylene glycol, and combinations thereof. The shell of the capsules may further include coloring agents, plasticizers, or fillers (e.g., certain starch or cellulose derivatives). If desired, the capsules can include an outer coating, such as a moisture barrier coating. Exemplary moisture barrier coating agents include hydrophobic compounds such as various waxes (e.g., canauba wax).

In certain embodiments, the shell of the capsules used in the invention include one more hydrocolloids such as gellan gum, agar, carrageenan, alginate, arabic gum, pectin, pullulan gum, or mannan gum, optionally in combination with gelatin.

Exemplary capsules can be of the type employed commercially in cigarettes marketed under the brand name Camel Crush by R.J. Reynolds Tobacco Company. That is, the capsules of the present invention, though possibly different in dimension (e.g., smaller in diameter) as compared to the capsules utilized in the Camel Crush product, can be manufactured using similar types of manufacturing techniques and ingredients.

See also the capsule technologies set forth in U.S. Pat. Nos. 3,550,598 to McGlumphy; 3,575,180 to Carty; 4,865,056 to Tamaoki et al.; 4,889,144 to Tateno et al.; 5,004,595 to Cherukuri et al.; 5,186,185 to Mashiko et al.; 5,331,981 to Tamaoki et al.; 5,690,990 to Bonner; 5,724,997 to Smith et al.; 5,759,599 to Wampler et al.; 6,039,901 to Soper et al.; 6,045,835 to Soper et al.; 6,056,992 to Lew; 6,106,875 to Soper et al.; 6,117,455 to Takada et al.; 6,325,859 to DeRoos et al.; 6,482,433 to DeRoos et al.; 6,612,429 to Dennen; 6,929,814 to Bouwmeesters et al.; 7,249,605 to McAdam et al.; and 7,578,298 to Karles et al.; US Pat. Appl. Pub. Nos. 2004/0261807 to Dube et al.; 2006/0112964 to Jupe et al.; 2007/0012327 to Karles et al.; 2007/0062549 to Holton, Jr. et al.; 2007/0095357 to Besso et al.; 2007/0186941 to Holton, Jr. et al.; 2008/0029110 to Dube et al.; 2008/0156336 to Wyss-Peters et al.; 2009/0038628 to Shen et al.; and 2009/0050163 to Hartmann et al.; and PCT WO 03/009711 to Kim; each of which is incorporated herein by reference.

Microcapsules are commercially available, and exemplary types of microcapsule technologies are set forth in Gutcho, Microcapsules and Microencapsulation Techniques (1976); Gutcho, Microcapsules and Other Capsules Advances Since 1975 (1979); Kondo, Microcapsule Processing and Technology (1979); and Iwamoto et al., AAPS Pharm. Sci. Tech. 2002 3(3): article 25, each of which is incorporated herein by reference. Exemplary types of commercially available microencapsulating techniques include those marketed under the trade names ULTRASEAL® and PERMASEAL® available from Givaudan headquartered in Vernier, Switzerland.

Manners and methods for incorporating both the adsorbent material and flavor capsules into desired regions of the filter element can vary. Typically, granules of carbonaceous material can be incorporated into “dalmation” types of filter regions using the general types of techniques used for traditional dalmation filter manufacture. Techniques for production of dalmation filters are known, and representative dalmation filters have been provided commercially by Filtrona Greensboro Inc. Flavor capsules can be incorporated into “cavity” types of filter regions using the general types of techniques used for traditional “cavity” filter manufacture. See, for example, the types of equipment and techniques that can be used for, or suitably modified for use for, incorporating materials into filters that are set forth in U.S. Pat. Nos. 3,844,200 to Sexstone; 4,016,830 to Sexstone; 4,214,508 to Washington; 4,425,107 to Hall; 4,411,640 to Hall; 5,322,495 to Budjinski II et al; 5,656,412 to Ercelebi et al and 6,837,281 to Spiers et al.; which are incorporated herein by reference. Other arrangements for inserting objects into filter material are disclosed, for example, in U.S. Pat. No. 7,115,085 to Deal; US Pat. Appl. Pub. Nos. 2007/0068540 to Thomas et al.; 2008/0029118 to Nelson et al.; 2008/0142028 to Fagg; 2008/0302373 to Stokes et al; 2009/0288667 to Andresen et al.; 2009/0288672 to Hutchens and 2010/0101589 to Nelson et al.; and U.S. patent application Ser. No. 12/407,260, filed Mar. 19, 2009, which are incorporated herein by reference.

Various types of cigarette components, including tobacco types, tobacco blends, top dressing and casing materials, blend packing densities, and types of paper wrapping materials for tobacco rods, can be employed. See, for example, the various representative types of cigarette components, as well as the various cigarette designs, formats, configurations and characteristics, that are set forth in Johnson, Development of Cigarette Components to Meet Industry Needs, 52^(nd) T.S.R.C. (September, 1998); U.S. Pat. Nos. 5,101,839 to Jakob et al.; 5,159,944 to Arzonico et al.; 5,220,930 to Gentry and 6,779,530 to Kraker; US Pat. Appl. Pub. Nos. 2005/0016556 to Ashcraft et al.; 2005/0066986 to Nestor et al.; 2005/0076929 to Fitzgerald et al.; 2006/0272655 to Thomas et al.; 2007/0056600 to Coleman, III et al.; and 2007/0246055 to Oglesby, each of which is incorporated herein by reference. Most preferably, the entire smokable rod is composed of smokable material (e.g., tobacco cut filler) and a layer of circumscribing outer wrapping material.

The wrapping material used as the tipping material and the plug wrap (i.e., the outer wrapping layers of the filter element 26), or used as the wrapping material 16 for the smokable rod, can be constructed using conventional paper wrapping materials. Typically, the wrapping material comprises a fibrous material and at least one filler material imbedded or dispersed within the fibrous material. The fibrous material can vary, but is typically a cellulosic material. The filler material typically has the form of essentially water insoluble particles, and may incorporate inorganic components. Exemplary filler materials include calcium carbonate, calcium tartrate, magnesium oxide, magnesium hydroxide gels; magnesium carbonate, clays, diatomaceous earth materials, titanium dioxide, gamma alumina materials, and calcium sulfate particles.

Exemplary types of wrapping materials, wrapping material components, and treated wrapping materials are described in U.S. Pat. Nos. 4,804,002 to Herron; 4,941,486 to Dube et al.; 5,105,838 to White et al.; 5,271,419 to Arzonico et al. 5,220,930 to Gentry; 5,490,875 to Wermers et al.; 6,706,120 to Miyauchi et al.; 7,195,019 to Hancock et al.; 7,237,559 to Ashcraft et al.; and 7,275,548 to Hancock et al.; US Pat. Appl. Pub. Nos. 2003/0114298 to Woodhead et al.; 2003/0131860 to Ashcraft et al. and 2004/0237980 to Holmes; PCT WO 01/08514 to Fournier et al.; and PCT WO 03/043450 to Hajaligol et al.; which are incorporated herein by reference. Representative wrapping materials are commercially available as R.J. Reynolds Tobacco Company Grades 119, 170, 419, 453, 454, 456, 465, 466, 490, 525, 535, 557, 652, 664, 672, 676 and 680 from Schweitzer-Maudit International. The porosity of the wrapping materials can vary, and frequently is between about 0 CORESTA units and about 100 CORESTA units, often between about 10 CORESTA units and about 90 CORESTA units, and frequently between about 20 CORESTA units and about 80 CORESTA units.

The wrapping materials used in the construction of cigarettes are adhered together using suitable adhesive compositions. Typical adhesive compositions used to adhere the seam of the plug wrap, the seam of the tobacco rod wrapper, and to adhere the tipping paper to the plug wrap are water-based formulations comprising a polymer emulsion. An exemplary aqueous polymer emulsion contains ethylene vinyl acetate copolymer, typically with one or more stabilizers such as a polyvinyl alcohol resin.

A flavorant can be incorporated into any of the cigarette wrapping materials (e.g., the tobacco rod wrapper, plug wrap, or tipping paper) in order to enhance the sensory characteristics of the smoking article. For example, the presence of a flavorant in the wrapping material could serve to mask or ameliorate any off-taste or malodor attributable to the wrapping materials or some component thereof. Exemplary flavorants for use in wrapping materials include methyl cyclopentenolone, heliotropin, vanillin, ethyl vanillin, caryophyllene oxide, 4-parahydroxyphenyl-2-butanone, gamma-undecalactone, gamma-dodecalactone, 2-methoxy-4-vinylphenol, 2-methoxy-4-methylphenol, 5-ethyl-3-hydroxy-4-methyl-2(5H)-furanone, methyl salicylate, clary sage oil, and sandalwood oil. In certain embodiments, the flavorants used in the wrapping materials have low vapor pressures, do not have a tendency to migrate or evaporate under normal ambient conditions, and are stable under the processing conditions experienced by wrapping materials for smoking articles.

A flavorant can be incorporated into a wrapping material in a variety of ways. The flavorant could be printed onto a paper wrapping material. The flavorant could also be incorporated into the structure of the paper wrapping material by imbedding flavorant particles within a wrapping material or adhering flavorant particles to a wrapping material. The flavorant could also be incorporated into coating formulations applied to a wrapping material or incorporated into any of the various adhesive materials (e.g., seam adhesives) used with cigarette wrapping materials. In one example, one or more flavorants are incorporated into side seam adhesive CS-2201A available from R.J. Reynolds Tobacco Company. Typically, flavorants are incorporated into coating compositions or adhesive compositions in amounts of about 0.01 percent to about 6.0 percent, based on the total weight of the composition. The flavorant incorporated into a wrapping material according to the invention can be any flavorant discussed herein.

The filter material utilized in various segments of the filter element (e.g., segments or regions 32, 36) can vary, and can be any material of the type that can be employed for providing a tobacco smoke filter for cigarettes. Typically, a traditional cigarette filter material is used, such as cellulose acetate tow, gathered cellulose acetate web, polypropylene tow, gathered cellulose acetate web, gathered paper, strands of reconstituted tobacco, or the like. In one embodiment, the filter segments are constructed of a filamentary or fibrous tow such as cellulose acetate, polyolefins such as polypropylene, or the like.

Where a fibrous tow is used as the filter material in certain filter segments, such as the two filter segments 32, 36 defining a cavity therebetween in FIG. 2, the fibrous tow of each region can vary in denier per filament (i.e., dpf where denier is expressed in units of g/9000 m) and total denier. Denier per filament is a measurement of the weight per unit length of the individual filaments of the tow, and can be manipulated to achieve a desired pressure drop across the filter segment. An exemplary dpf range for the fibrous tow used in the filter element of the invention is about 1.5 to about 8. An exemplary range of total denier for fibrous tow used in the present invention is about 10,000 to about 50,000 (e.g., about 15,000 or about 40,000 total denier). See also the types of filter materials set forth in U.S. Pat. Nos. 3,424,172 to Neurath; 4,811,745 to Cohen et al.; 4,925,602 to Hill et al.; 5,225,277 to Takegawa et al.; and 5,271,419 to Arzonico et al.; each of which is incorporated herein by reference.

The fibrous tow used in each segment of the filter element can be identical, but in some cases, each segment of the filter element will contain a fibrous tow with a different dpf and total denier in order to establish different pressure drop values across each segment. In one embodiment, the filter segment 32 closest to the tobacco end of the filter element has a dpf of about 1.5 to about 7 and a total denier of about 15,000 to about 35,000. The tobacco end segment will typically have the same or a lower dpf value as compared to the mouth end segment. In one embodiment, the filter segment 36 closest to the mouth end of the filter element has a dpf of about 5 to about 7 and a total denier of about 15,000 to about 30,000.

Normally, a plasticizer such as triacetin or carbowax is applied to the filamentary tow in traditional amounts using known techniques. In one embodiment, the plasticizer component of the filter material comprises triacetin and carbowax in a 1:1 ratio by weight. The total amount of plasticizer is generally about 4 to about 20 percent by weight, preferably about 6 to about 12 percent by weight. Other suitable materials or additives used in connection with the construction of the filter element will be readily apparent to those skilled in the art of cigarette filter design and manufacture. See, for example, U.S. Pat. No. 5,387,285 to Rivers, which is incorporated herein by reference.

The dimensions of a representative cigarette can vary. Preferred cigarettes are rod-shaped, and can have a circumference of about 12 mm to about 30 mm, often about 16 mm to about 25 mm; and can have a total length of about 70 mm to about 120 mm, often about 90 mm to about 110 mm.

The length of the filter element 26 can vary. Typical filter elements can have total lengths of about 20 mm to about 40 mm, often about 20 mm to about 30 mm. Referring to the embodiment of FIG. 2, the length of the mouth end segment of filter material 36 is often about 8 mm to about 12 mm, the length of the central cavity 34 is often about 5 mm to about 8 mm, and the length of the tobacco end segment of filter material 32 is often about 8 to about 12 mm.

Typically, pressure drop values of cigarettes, which correspond to resistance to draw, are measured using a Filtrona Cigarette Test Station (CTS Series) available form Filtrona Instruments and Automation Ltd. Pressure drop can be expressed as mm of water required to draw 17.5 cc/sec of air through or across the filter region from the tobacco rod side to the mouth end of the filter element. An exemplary cigarette exhibits a pressure drop of between about 100 and about 300 mm water pressure drop at 17.5 cc/sec air flow. Preferred cigarettes exhibit pressure drop values of between about 150 mm and about 200 mm water pressure drop at 17.5 cc/sec air flow.

The filter element 26 will often have a total pressure drop of about 80 mm water to about 120 mm water. In the filter configuration of FIG. 2, the pressure drop across the mouth end segment of filter material 36 is often about 15 mm water to about 45 mm water (e.g., about 18 to about 30 mm water), the pressure drop across the central cavity 34 is often about 2 mm water to about 6 mm water, and the pressure drop across the tobacco end segment of filter material 32 is often about 40 to about 80 mm water. The pressure drop across the filter segment 32 closest to the tobacco rod is typically the same or higher than the pressure drop across the filter segment 36 distal from the tobacco rod.

For cigarettes that are air diluted or ventilated, the amount or degree of air dilution or ventilation can vary. Frequently, the amount of air dilution for an air diluted cigarette is greater than about 10 percent, generally is greater than about 20 percent, often is greater than about 30 percent, and sometimes is greater than about 40 percent. Typically, the level of air dilution for an air diluted cigarette is less than about 80 percent, and often less than about 70 percent. As used herein, the term “air dilution” is the ratio (expressed as a percentage) of the volume of air drawn through the air dilution means to the total volume and air and smoke drawn through the cigarette and exiting the extreme mouth end portion of the cigarette.

Filter element components or segments for filter elements for multi-segment filtered cigarettes typically are prepared from filter rods using the types of rod-forming units that traditionally have been employed to provide multi-segment cigarette filter components, such as those available as KDF-2 and KDF-3E from Hauni-Werke Korber & Co. KG. Typically, filter material, such as filter tow, is provided using a tow processing unit. An exemplary tow processing unit capable of processing cellulose acetate tow has been commercially available as E-60 supplied by Arjay Equipment Corp., Winston-Salem, N.C. Other exemplary tow processing units have been commercially available as AF-2, AF-3, and AF-4 from Hauni-Werke Korber & Co. KG. In addition, representative manners and methods for operating a filter material supply units and filter-making units are set forth in U.S. Pat. Nos. 4,281,671 to Byrne; 4,862,905 to Green, Jr. et al.; 5,060,664 to Siems et al.; 5,387,285 to Rivers; and 7,074,170 to Lanier, Jr. et al., which are incorporated herein by reference. Other types of technologies for supplying filter materials to a filter rod-forming unit are set forth in U.S. Pat. Nos. 4,807,809 to Pryor et al. and 5,025,814 to Raker, which are incorporated herein by reference.

Multi-segment filter elements typically are provided from so-called “six-up” filter rods, “four-up” filter rods and “two-up” filter rods that are of the general format and configuration conventionally used for the manufacture of filtered cigarettes can be handled using conventional-type or suitably modified cigarette rod handling devices, such as tipping devices available as Lab MAX, MAX, MAX S or MAX 80 from Hauni-Werke Korber & Co. KG. See, for example, the types of devices set forth in U.S. Pat. Nos. 3,308,600 to Erdmann et al.; 4,281,670 to Heitmann et al.; 4,280,187 to Reuland et al.; 4,850,301 to Greene, Jr. et al.; and 6,229,115 to Vos et al.; and US Pat. Appl. Pub. Nos. 2005/0103355 to Holmes, 2005/1094014 to Read, Jr., and 2006/0169295 to Draghetti, each of which is incorporated herein by reference.

Representative types of filter designs and components, including representative types of segmented cigarette filters, are set forth in U.S. Pat. Nos. 4,920,990 to Lawrence et al.; 5,012,829 to Thesing et al.; 5,025,814 to Raker; 5,074,320 to Jones, Jr. et al.; 5,105,838 to White et al.; 5,271,419 to Arzonico et al.; 5,360,023 to Blakley et al.; 5,396,909 to Gentry et al.; and 5,718,250 to Banerjee et al; US Pat. Appl. Pub. Nos. 2002/0166563 to Jupe et al., 2004/0261807 to Dube et al.; 2005/0066981 to Crooks et al.; 2006/0090769 to Woodson et al.; 2006/0124142 to Zhang; 2006/0144412 to Mishra et al., 2006/0157070 to Belcastro et al.; and 2007/0056600 to Coleman, III et al.; PCT WO 03/009711 to Kim; and PCT WO 03/047836 to Xue et al., all of which are incorporated herein by reference.

Filter elements of the present invention can be incorporated within conventional cigarettes configured for combustion of a smokable material, and also within the types of cigarettes set forth in U.S. Pat. Nos. 4,756,318 to Clearman et al.; 4,714,082 to Banerjee et al.; 4,771,795 to White et al.; 4,793,365 to Sensabaugh et al.; 4,989,619 to Clearman et al.; 4,917,128 to Clearman et al.; 4,961,438 to Korte; 4,966,171 to Serrano et al.; 4,969,476 to Bale et al.; 4,991,606 to Serrano et al.; 5,020,548 to Farrier et al.; 5,027,836 to Shannon et al.; 5,033,483 to Clearman et al.; 5,040,551 to Schlatter et al.; 5,050,621 to Creighton et al.; 5,052,413 to Baker et al.; 5,065,776 to Lawson; 5,076,296 to Nystrom et al.; 5,076,297 to Farrier et al.; 5,099,861 to Clearman et al.; 5,105,835 to Drewett et al.; 5,105,837 to Barnes et al.; 5,115,820 to Hauser et al.; 5,148,821 to Best et al.; 5,159,940 to Hayward et al.; 5,178,167 to Riggs et al.; 5,183,062 to Clearman et al.; 5,211,684 to Shannon et al.; 5,240,014 to Deevi et al.; 5,240,016 to Nichols et al.; 5,345,955 to Clearman et al.; 5,396,911 to Casey, III et al.; 5,551,451 to Riggs et al.; 5,595,577 to Bensalem et al.; 5,727,571 to Meiring et al.; 5,819,751 to Barnes et al.; 6,089,857 to Matsuura et al.; 6,095,152 to Beven et al; and 6,578,584 to Beven; which are incorporated herein by reference. Still further, filter elements of the present invention can be incorporated within the types of cigarettes that have been commercially marketed under the brand names “Premier” and “Eclipse” by R.J. Reynolds Tobacco Company. See, for example, those types of cigarettes described in Chemical and Biological Studies on New Cigarette Prototypes that Heat Instead of Burn Tobacco, R.J. Reynolds Tobacco Company Monograph (1988) and Inhalation Toxicology, 12:5, p. 1-58 (2000); which are incorporated herein by reference.

Cigarette rods typically are manufactured using a cigarette making machine, such as a conventional automated cigarette rod making machine. Exemplary cigarette rod making machines are of the type commercially available from Molins PLC or Hauni-Werke Korber & Co. KG. For example, cigarette rod making machines of the type known as MkX (commercially available from Molins PLC) or PROTOS (commercially available from Hauni-Werke Korber & Co. KG) can be employed. A description of a PROTOS cigarette making machine is provided in U.S. Pat. No. 4,474,190 to Brand, at col. 5, line 48 through col. 8, line 3, which is incorporated herein by reference. Types of equipment suitable for the manufacture of cigarettes also are set forth in U.S. Pat. Nos. 4,781,203 to La Hue; 4,844,100 to Holznagel; 5,131,416 to Gentry; 5,156,169 to Holmes et al.; 5,191,906 to Myracle, Jr. et al.; 6,647,870 to Blau et al.; 6,848,449 to Kitao et al.; and 6,904,917 to Kitao et al.; and US Pat. Appl. Pub. Nos. 2003/0145866 to Hartman; 2004/0129281 to Hancock et al.; 2005/0039764 to Barnes et al.; and 2005/0076929 to Fitzgerald et al.; each of which is incorporated herein by reference.

The components and operation of conventional automated cigarette making machines will be readily apparent to those skilled in the art of cigarette making machinery design and operation. For example, descriptions of the components and operation of several types of chimneys, tobacco filler supply equipment, suction conveyor systems and garniture systems are set forth in U.S. Pat. Nos. 3,288,147 to Molins et al.; 3,915,176 to Heitmann et al.; 4,291,713 to Frank; 4,574,816 to Rudszinat; 4,736,754 to Heitmann et al. 4,878,506 to Pinck et al.; 5,060,665 to Heitmann; 5,012,823 to Keritsis et al. and 6,360,751 to Fagg et al.; and US Pat. Appl. Pub. No. 2003/0136419 to Muller; each of which is incorporated herein by reference. The automated cigarette making machines of the type set forth herein provide a formed continuous cigarette rod or smokable rod that can be subdivided into formed smokable rods of desired lengths.

EXPERIMENTAL

The following examples are provided to illustrate embodiments of the present invention, and should not be considered to limit the scope thereof. Unless otherwise noted, all parts and percentages are by weight and on a dry basis.

Example 1

A cigarette is prepared using a representative American tobacco blend comprising burley tobacco, flue-cured tobacco, Oriental tobacco, and reconstituted tobacco materials. An aqueous casing material comprising humectant and flavor components is added to the tobacco blend and the blend is equilibrated to a moisture content of about 12-15 percent prior to cigarette manufacture.

The tobacco blend is incorporated into a tobacco rod, which is attached to a filter element in order to prepare a cigarette rod having a total length of about 108 mm with a filter element length of about 27 mm. The tobacco rod includes a tobacco charge weighing about 0.6 g contained within a circumscribing cigarette paper wrap of conventional type.

The filter element of the cigarette has the general configuration shown in FIG. 2, with a 10 mm mouth end segment constructed of plasticized cellulose acetate tow (5.0 dpf/30,000 total denier), a 5 mm central cavity filled with about 102 mg of menthol-containing capsules, and a 12 mm tobacco end “dalmation” segment constructed of plasticized cellulose acetate tow (1.8 dpf/35,000 total denier) and containing about 40 mg of G277M activated carbon manufactured by PICA dispersed within the fibrous tow. The plasticizer used in each fibrous tow segment is triacetin. The filter element is circumscribed by a plug wrap having a paper weight of about 24 gsm.

The completed cigarette has a circumference of about 24 mm and a total pressure drop of about 150 mm H₂O. The filter element pressure drop is about 100 mm H₂O, with the mouth end segment having a pressure drop of about 18 mm H₂O, the cavity having a pressure drop of about 5 mm H₂O, and the tobacco end segment having a pressure drop of about 77 mm H₂O. The filter element of the cigarette comprises both an upstream adsorbent material and downstream capsules that can be selectively ruptured by the smoker to add a menthol flavor to mainstream smoke.

Example 2

A cigarette is prepared that is similar to the embodiment of Example 1, except for the following changes:

-   -   (1) the mouth end segment is a cellulose acetate tow having a         6.8 dpf and a total denier of 15,000, and the pressure drop         across the segment is about 28 mm H₂O;     -   (2) the central cavity is filed with about 63 mg of capsules and         has a pressure drop of about 3 mm H₂O;     -   (3) the tobacco end segment is a cellulose acetate tow having a         6.8 dpf and a total denier of 15,000, and the pressure drop         across the segment is about 50 mm H₂O;     -   (4) the combined pressure drop across the cigarette rod is about         150 mm H₂O;     -   (5) the tobacco end segment has an activated carbon load of         about 15 mg; and     -   (6) the circumference of the cigarette rod is about 16 mm.

Example 3

A cigarette is prepared that is similar to the embodiment of Example 2, except for the following changes:

-   -   (1) the mouth end segment has a pressure drop of about 43 mm         H₂O;     -   (2) the central cavity has a length of about 7 mm and a pressure         drop of about 4 mm H₂O; and     -   (3) the tobacco end segment has a length of about 10 mm and a         pressure drop of about 43 mm H₂O.

Many modifications and other embodiments of the invention will come to mind to one skilled in the art to which this invention pertains having the benefit of the teachings presented in the foregoing description; and it will be apparent to those skilled in the art that variations and modifications of the present invention can be made without departing from the scope or spirit of the invention. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation. 

1. A filter element for a smoking article, comprising (a) a first segment of fibrous tow filter material; (b) a second segment of fibrous tow filter material in spaced relation to the first segment; and (c) a cavity positioned between the two segments (a) and (b) of fibrous tow filter material, the cavity containing a plurality of breakable capsules comprising an outer shell and an internal payload comprising a flavorant; wherein segment (a) of fibrous tow filter material comprises an adsorbent material dispersed therein and segment (b) is substantially free of adsorbent material.
 2. The filter element of claim 1, wherein the adsorbent material is selected from the group consisting of activated carbon, molecular sieves, clay, ion exchange resins, activated alumina, silica gel, meerschaum, oxidation catalysts, and combinations thereof.
 3. The filter element of claim 1, wherein the adsorbent material is a carbonaceous material.
 4. The filter element of claim 1, wherein the flavorant is selected from the group consisting of vanilla, coffee, chocolate, cream, mint, spearmint, menthol, peppermint, wintergreen, lavender, cardamon, nutmeg, cinnamon, clove, cascarilla, sandalwood, honey, jasmine, ginger, anise, sage, licorice, lemon, orange, apple, peach, lime, cherry, eucalyptus, strawberry, and mixtures thereof.
 5. The filter element of claim 1, wherein the flavorant is a cooling agent.
 6. The filter element of claim 1, wherein the payload of the breakable capsules is anhydrous.
 7. The filter element of claim 1, wherein the payload of the breakable capsules comprises a mixture of the flavorant with a diluting agent.
 8. The filter element of claim 7, wherein the diluting agent comprises a mixture of C6-C12 triglycerides.
 9. The filter element of claim 1, wherein the breakable capsules are generally spherical in shape with a diameter in the range of about 0.75 mm to about 2.5 mm.
 10. The filter element of claim 9, wherein the cavity (c) contains a sufficient number of breakable capsules such that the void space in the cavity is less than about 50 percent of the volume of the cavity.
 11. The filter element of claim 10, wherein the cavity (c) contains a sufficient number of breakable capsules such that the void space in the cavity is less than about 30 percent of the volume of the cavity.
 12. The filter element of claim 1, wherein the thickness of the shell of the breakable capsules is in the range of about 50 to about 200 microns and the ratio of the diameter of the capsule to the thickness of the shell is about 10 to about
 100. 13. The filter element of claim 1, wherein the cavity (c) contains about 20 to about 120 generally spherical breakable capsules having a diameter in the range of about 1 mm to about 1.5 mm.
 14. The filter element of claim 1, wherein the breakable capsules have a crush strength in the range of about 0.1 to about 4.0 kp.
 15. The filter element of claim 1, wherein the breakable capsules have a crush strength in the range of about 0.2 to about 1.5 kp.
 16. The filter element of claim 1, wherein the material forming the shell of the breakable capsules is selected from the group consisting of gelatin, gum arabic, polyvinyl acetate, alginates, carob bean gum, potassium citrate, carrageenan, citric acid, dextrin, polyvinyl alcohol, povidone, dimethylpolysiloxane, dimethyl silicone, bleached shellac, guar gum, gellan gum, agar, ghatti gum, mannan gum, pullulan gum, modified starch, cellulosic materials, sodium citrate, sodium ferrocyanide, locust bean gum, polyphosphates, tannic acid, petroleum wax, terpene resin, tragacanth, polyethylene, xanthan gum, polyethylene glycol, and combinations thereof.
 17. The filter element of claim 1, wherein the material forming the shell of the breakable capsules comprises a hydrocolloid selected from the group consisting of gellan gum, agar, carrageenan, alginate, arabic gum, pectin, pullulan gum, mannan gum, and combinations thereof, optionally in combination with gelatin.
 18. The filter element of claim 1, wherein the breakable capsules include an outer moisture barrier coating.
 19. The filter element of claim 1, wherein the length of the first segment of fibrous tow filter material (a) is about 8 mm to about 12 mm, the length of the cavity (c) is about 5 mm to about 8 mm, and the length of second segment of fibrous tow filter material (b) is about 8 to about 12 mm.
 20. The filter element of claim 1, wherein the combined pressure drop across the first segment (a), the second segment (b), and the cavity (c) is between about 80 mm water and about 120 mm water.
 21. The filter element of claim 1, wherein the pressure drop across the first segment (a) is the same or higher than the pressure drop across the second segment (b).
 22. The filter element of claim 21, wherein the pressure drop across the first segment (a) is about 40 to about 80 mm water and the pressure drop across the second segment (b) is about 15 mm water to about 45 mm water.
 23. The filter element of claim 1, further comprising a particulate material mixed with the capsules, the particulate material adapted to assist rupture of the capsules.
 24. A cigarette comprising a tobacco rod comprising a smokable filler material contained within a circumscribing wrapping material and a filter element according to claim 1 connected to the tobacco rod at one end thereof.
 25. The cigarette of claim 24, wherein the circumscribing wrapping material comprises a side seam adhesive, and the side seam adhesive comprises a flavorant.
 26. A filter element for a smoking article, comprising (a) a first segment of cellulose acetate tow filter material; (b) a second segment of cellulose acetate tow filter material in spaced relation to the first segment; and (c) a cavity positioned between the two segments (a) and (b) of fibrous tow filter material, the cavity containing about 20 to about 120 generally spherical breakable capsules having a diameter in the range of about 1 mm to about 1.5 mm and a crush strength in the range of about 0.2 to about 1.5 kp, the breakable capsules comprising an outer shell and an internal payload comprising a flavorant and a diluting agent; wherein segment (a) of fibrous tow filter material comprises a carbonaceous material dispersed therein and segment (b) is substantially free of carbonaceous material.
 27. The filter element of claim 26, wherein the flavorant is menthol.
 28. A cigarette comprising a tobacco rod comprising a smokable filler material contained within a circumscribing wrapping material and a filter element according to claim 26 connected to the tobacco rod at one end thereof. 